am 3e371e2e: dalvik: thread: Set the control group of a thread to the background group if the priority is logically-lower than ANDROID_PRIORITY_BACKGROUND

Merge commit '3e371e2ebbeeefe176ba1357e6ff241bd13a711e'

* commit '3e371e2ebbeeefe176ba1357e6ff241bd13a711e':
  dalvik: thread: Set the control group of a thread to the background group